1. Field of the Disclosure
This disclosure relates to a backlight unit, and more particularly, to a backlight unit having improved reliability, and a liquid crystal display (LCD) device having the backlight unit.
2. Description of the Related Art
Display devices used for computer monitors or TVs include self-light emitting devices such as organic light emitting displays (OLEDs), vacuum fluorescent displays (VFDs), field emission displays (FEDs), and plasma display panels (PDPs), and non self-light emitting devices such as liquid crystal displays (LCDs). A general LCD device includes two substrates having electric field generation electrodes and a liquid crystal layer having dielectric anisotropy and interposed between the substrates. When a voltage is applied to the electric field generation electrodes, an electric field is generated in the liquid crystal layer. The strength of the electric field is adjusted by changing the voltage. Thus, a desired image is displayed by controlling transmissivity of light passing through the liquid crystal layer.
The LCD device includes a data driver externally receiving image data and generating data signals of respective pixels and supplying the generated data signals to data lines of an LCD panel, a gate driver generating a gate signal to drive pixels of the LCD panel by one line and supplying the generated gate signal to respective gate line of the LCD panel, and a backlight unit disposed on the rear surface of the LCD panel and providing light.
Cold cathode fluorescent lamps (CCFLs), external electrode fluorescent lamps (EEFLs), or light emitting diodes (LEDs) are used as a light source of a general backlight unit. Recently, the LEDs are widely used as a light source of a backlight unit due to it merits such as high light efficiency, miniaturization capability, low power consumption.
In a backlight unit having the LEDs, a printed circuit board (PCB) or a flexible printed circuit board (FPC) is arranged at an inner side of the backlight unit. A plurality of LEDs are mounted on the PCB or FPC. The LED is a combination of a red LED, a green LED, and a blue LED, respectively, emitting red, green, and blue lights. Since the backlight unit configured as above provides a white light mixed with the red, green, and blue lights to the LCD panel, the red, green, and blue LEDs emitting red, green, and blue lights, respectively, need to be controlled.